Offline data authentication (ODA) lets the terminal check, without the issuer, that the card's data — and for DDA and CDA the card itself — is genuine. It rests on a three-level RSA chain described in EMV Book 2.
Offline data authentication
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SDA, DDA and CDA: the certificate chain, the CAPK, the hashes, and every way they fail.
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The opening of the article
In the full article
- The three methods
- Recovering the keys
- CDA in detail
- Every way it fails
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